“AT&T’s elimination of T-Mobile as an independent, low- priced rival would remove a significant competitive force from the market,” the U.S. said.

I’m actually a little shocked at this news. While a number of issues have been brought fourth over the last few weeks that did not favor AT&T, I was under the impression that most analysts predicted that this acquisition would still happen. And this doesn’t necessarily mean that it won’t happen, it just means it could be a lot trickier.

Update: AT&T has released a statement, and boy do they not sound pleased:

We are surprised and disappointed by today’s action, particularly since we have met repeatedly with the Department of Justice and there was no indication from the DOJ that this action was being contemplated.

We plan to ask for an expedited hearing so the enormous benefits of this merger can be fully reviewed. The DOJ has the burden of proving alleged anti-competitive affects and we intend to vigorously contest this matter in court.

At the end of the day, we believe facts will guide any final decision and the facts are clear. This merger will:

Help solve our nation’s spectrum exhaust situation and improve wireless service for millions.

Allow AT&T to expand 4G LTE mobile broadband to another 55 million Americans, or 97% of the population;

Result in billions of additional investment and tens of thousands of jobs, at a time when our nation needs them most.

We remain confident that this merger is in the best interest of consumers and our country, and the facts will prevail in court.

Update 2: And Sprint has now released a statement…

The DOJ today delivered a decisive victory for consumers, competition and our country. By filing suit to block AT&T’s proposed takeover of T-Mobile, the DOJ has put consumers’ interests first. Sprint applauds the DOJ for conducting a careful and thorough review and for reaching a just decision – one which will ensure that consumers continue to reap the benefits of a competitive U.S. wireless industry. Contrary to AT&T’s assertions, today’s action will preserve American jobs, strengthen the American economy, and encourage innovation.